1. Field of the Invention
The present invention relates to an audio apparatus, and is preferably applied to a noise-canceling apparatus, for example.
2. Description of the Related Art
There is a noise canceling headphone including a microphone: The noise canceling headphone is designed to collect noise around a user, invert it and then supply it from a driver unit to a headphone to cancel the noise (see Jpn. Pat. Laid-open Publication No. 2002-330485, for example).
The noise canceling headphone includes a plug on which there are plug terminals. If a microphone input terminal and a speaker output terminal are placed parallel to the plug-pulling insertion direction, the speaker output terminal on the plug may contact the microphone input terminal on a connector when the plug is pulled out of the connector. This may cause oscillation (so-called howling) due to an output signal from a speaker which returns to the microphone.
Accordingly, an audio apparatus, to which the noise canceling headphone is connected, may have a switch system to prevent the oscillation from happening. In this case, the audio apparatus includes a switch connected to wires in a cable, whose rod-like switch lever is parallel to the plug-pulling insertion direction. When the plug is being inserted into a jack a tip end section of the switch lever touches an end surface of the jack. When the plug has been inserted into the jack completely the end surface pushes the switch lever to open the switch (see Jpn. Pat. Laid-open Publication No. H5-31161, for example).
In addition, the audio apparatus may include a connection detection system for F-type connector to detect whether the headphone is connected. This allows the audio apparatus to output a signal to a different section when the noise canceling headphone is connected to the audio apparatus while the audio apparatus outputs a signal to a certain section when an ordinary headphone with no microphone is connected to the audio apparatus (see Jpn. Pat. Laid-open Publication No. 2006-164669, for example).